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Japanning Trial

Started by NorthernElectric, April 17, 2015, 07:54:05 PM

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Jack Ryan

I have long thought about suitable methods of refinishing items that were originally black japanned.

Black paint can look OK but if the item is actually used, the paint soon comes off.

Products like Black Jack are bitumen based but not cured. Subsequent application of solvent will remove the finish - it is really only waterproofing. I don't know what the application of heat will do to the finish or how it might change its physical properties (if it will cure).

Black japan covers a lot of different finishes but as applied to metal - cars and telephones - it is cured producing a very tough finish. It is hard but does not immediately break or chip if the metal is dented.

I believe black japan uses asphaltum rather than just bitumen. It is a harder and less volatile form of bitumen.

Asphaltum typically designates a species of bitumen, including dark colored, comparatively hard and non-volatile solids; composed of hydrocarbons, substantially free from oxygenated bodies and crystallizable paraffin; sometimes associated with mineral matter, the non-mineral constituents being difficultly fusible and largely soluble in carbon disulfide; the distillation residue yields considerable sulfonation residue. This definition includes Gilsonite and glance pitch.

https://www.naturalpigments.com/artist-materials/asphaltum-bitumen/


Ford used Gilsonite in its black japan mixture (https://en.wikipedia.org/wiki/Japan_black).

Western Electric's formula for black japan changed - the B Handset Mounting was finished in "rubber finish japan".

The japan used at the present time produces a semi -dull black finish having the appearance of a machined and polished piece of hard rubber from which it derives its name. The name -"rubber finish japan " -is somewhat misleading, however, in that the japan contains no rubber.

(Bell-Laboratories-Record-1930-12)


There's always powder coating...

Jack


FABphones

Totally agree about curing needing to be considered. My latest 'build' was trailing engine oil and heated metal which at the moment is my preferred method. Haven't quite got to the stage of chucking a No150 stick in there yet (which is where I was headed with this). Shame our place didn't have an old Forge, I could have put it to good use.

Powder coating (without sending the parts away) I have not looked into.
Never keen to send parts off, for me, not an easy service to find, and if the parts go missing....  :(
A collector of  'Monochrome Phones with Sepia Tones'   ...and a Duck!
***********
Vintage Phones - 10% man made, 90% Tribble
*************

TelePlay

Christian was getting good at doing his own powder coating at home but it always seemed too complicated for me to get into and sending out is dicey including ending up with an off shade color. Always felt a paint like coating baked or cured on metal was the best solution.

Doing a bit of research, discovered some bitumen materials are used in roof work including patching but those are more tar like, not paints. But some bitumen paints do dry to a gloss like finish. Dry vs cure goes to baking in that all finishes "cure" to some degree as the volatile components, carrier solvents evaporate and the "paint" molecules link together and "cure." Controlled heating does have an impact on curing.  Baked finishes are "harder" than air dried finishes.

They use bitumen coatings on steel pipe buried in the ground to carry crude to water, the coating they use is a tough, hard, smooth, rust proof finish so this type of coating seems to be similar to Asphaltium original Ford cars and WE phone coating.

Black Jack is not sold in the US and haven't found an equivalent yet. Now that I have reinstalled my baking setup with a larger oven, I would also be interested in playing with this stuff including the addition of thinners and agents that do cure, link together to create a hard, tough shiny surface. But I can't find Black Jack so that's now a back burner project.

Will be waiting to see what others discover.

Jim Stettler

I googled 'diy japanned finish'
there  are some people experimenting with it
Here is a couple posts from the search

ASPHALTUM IS ALSO A PRINTMAKING SUPPLY. AVAILABLE FROM PRINTING SUPPLY CO OR FROM A GOOD ART SUPPLY STORE THAT SELLS ETCHING SUPPLIES. IT COMES IN A CHUNK AND MELTS TO DRAW LIKE A CRAYON ON A WARMED PRINTING PLATE. HARDENS WHEN COOL AGAIN.
-------------------------------------------------------------------------------------------
Cold Mix Japanning Recipe:
Add 2 parts linseed oil, 5 parts turpentine, and 3 parts asphaltum powder to your glass jar jar. ...
Stir the mixture a bit and cover.
it dissolve for 2-3 days. ...
You may still have a bit of asphaltum on the jar's bottom that doesn't dissolve. ...
Test the mixture's thickness. ...
Check your test.
You live, You learn,
You die, you forget it all.

TelePlay

This 6 year old topic also has info on the "mix it yourself at home" recipes including a link to a Japanning Handbook published in 1913.

http://www.classicrotaryphones.com/forum/index.php?topic=11853.0

If this bitumen paint (with some additives, thinning and/or heating) comes close to the original Japanning mixture, that would be easier than finding all the original chemicals and melting them together.

I did find this distinction between bitumen and asphaltum on an artist site:  "Asphaltum is pigment melted into turps; Bitumen is pigment ground in oil." Bitumen paint as such must then also have volatile carriers that evaporate leaving the pigment to dry like paint instead of an oil paint on canvas that never fully dries or cures.

I guess that's why to original japanning mixture was created by heating, to melt the asphaltum where bitumen does not melt.

As in the past, this is a very complex area of research using not so nice compounds.




FABphones

Quote from: TelePlay on October 04, 2020, 10:37:05 AM
..."Asphaltum is pigment melted into turps; Bitumen is pigment ground in oil." Bitumen paint as such must then also have volatile carriers that evaporate leaving the pigment to dry like paint instead of an oil paint on canvas that never fully dries or cures...

This is my experience with the product I use.
A collector of  'Monochrome Phones with Sepia Tones'   ...and a Duck!
***********
Vintage Phones - 10% man made, 90% Tribble
*************

Jack Ryan

Quote from: TelePlay on October 04, 2020, 10:37:05 AM
I did find this distinction between bitumen and asphaltum on an artist site:  "Asphaltum is pigment melted into turps; Bitumen is pigment ground in oil."

I think that is artistic license, asphaltum is a naturally occurring solid hydrocarbon bitumen. The more general bitumen is also naturally occurring but includes much more volatile variants.

Jack


countryman

The old recipes contain asphalt/bitumen, a solvent and linseed oil. The latter is often used for painting, as it dries and gives a glossy surface. This  "drying" is more a polymerization, the oil molecules oxidize when exposed to the air and turn into a solid coating.
The paint will "dry" by the evaporation of the turpentine, leaving behind more or less solid asphalt, and by the polymerization of the linseed oil.
The original poster of this thread suggested to combine a building bitumen product and varnish - the idea behind it seems to be the same, and the result obtained wasn't too bad!

I hoped the "MIPA Bitumen-Lack" I accidentally found would be a ready-to-use compound acting in the same way.
After the earlier trials on small parts I now did a piece of steel plate. I failed to clean the sanding dust properly, please ignore the spots in the paint. Otherwise I like the result, one layer of the paint covers the metal well and has a good but not excessive "deep" gloss. The paint is not runny, dries within 2 hours and is easy to work with - I guess all these properties made it the favorite of any hardware manufacturer before synthetic resin lacquers appeared.
The trial has cured for 24 hours now and can be handled normally without leaving fingerprints or a sticky feeling. I went ahead and wiped over it with an acetone drenched rag. As expected, this will lift off some paint, as it also does on the old phone's original coating to a somewhat lesser degree. Baking the paint or simply a longer curing time might help here.
At the moment I do not have much spare time so the actual restoration of the OB05 will happen later. But I think the product I tried is acceptable to be used on them.
I hope the product is not a discontinued item, as I can't find it on the MIPA homepage ?!

FABphones

Thanks for the progress update. Would you add a photo of the rear of can showing the list of contents?

In a hardware store today they had Black Jack, so I bought a can. I won't be joining you in experimenting for some time but I thought I would get it meantime anyhow.

Screenshot of front of can and content list (from rear) below:
A collector of  'Monochrome Phones with Sepia Tones'   ...and a Duck!
***********
Vintage Phones - 10% man made, 90% Tribble
*************

Jim Stettler

side note regarding linseed oil and oil based paint.
My father decided to use linseed oil on  the handles of his garden tools. He had a bit of leftover green oil-based paint. and decided  to use that with  linseed oil.

the paint never dried,  we wrapped the handles in tape so you could use them without getting a green hand.
10 years later it was still tacky. It became a family  joke .
Jim
You live, You learn,
You die, you forget it all.

countryman

#25
From my experience I can confirm that mixing different types of paint does not always give the expected result  :o
Linseed oil comes in different grades, raw oil dries slowly or never, or it may be treated to dry quicker, and drying agents may be added, often lead compounds in the old recipes.

The rear side of the can is more or less an extract from this PDF:
https://shop.farbenmorscher.at/pcsartikelobjekte/tm/tm_MIPA_Bitumenlack.pdf

Contents: "Special Bitumen, aliphatic hydrocarbons".

Seems to speak against my thesis about drying/curing/lacquer-like components being involved...

FABphones

Quote from: countryman on October 06, 2020, 06:54:15 AM
The rear side of the can is more or less an extract from this PDF:
https://shop.farbenmorscher.at/pcsartikelobjekte/tm/tm_MIPA_Bitumenlack.pdf

Contents: "Special Bitumen, aliphatic hydrocarbons".


Teleplay, may I ask for your analysis/thoughts please. This is a bit beyond me.
We have mipa with 'special bitumen' (?) and 'aliphatic hydrocarbons' (??) and then bitumen and white spirit listed as the contents of Black Jack.
A collector of  'Monochrome Phones with Sepia Tones'   ...and a Duck!
***********
Vintage Phones - 10% man made, 90% Tribble
*************

countryman

If you asked me, my guess would be it's the same.

FABphones

Thanks for bringing this subject back into trial countryman, and thanks for sharing your projects.
All very interesting.  :)
A collector of  'Monochrome Phones with Sepia Tones'   ...and a Duck!
***********
Vintage Phones - 10% man made, 90% Tribble
*************

countryman

I now tried the bitumen paint to touch up chipped antique paint.
The condition of the old paint was not awful enough to strip it and repaint, but I tried to preserve the patina. I dabbed on the bitumen paint with a small brush on the damaged areas and let it cure for 45 minutes or so. It did not feel very sticky after this time, but still soft. I gently polished the object with a rag moistened with denatured alcohol. This took away much of the visible lines between old and new paint.